Ab initio calculations of electronic and optical properties of BeO nanosheet

The electronic and the linear optical properties of BeO nanosheet and wurtzite structure are investigated by using the full potential linear augmented plane wave plus local orbital (FPLAPW+ lo) in the frame work of the density functional theory (DFT). The dielectric tensor is derived within the random phase approximation (RPA). Specifically, dielectric function, absorption coefficient, optical conductivity, extinction index, loss function, reflectivity and the refraction index of the BeO nanosheet are calculated for both parallel and perpendicular electric field polarizations. The results show that the optical conductivity in E ‖ x starts with a gap about 5.89 eV confirms that BeO nanosheet has semiconductor property also the optical spectra are anisotropic along these two polarizations. The static refractive index of nanosheet is smaller than wurtzite structure.